ACL Injury and Rehabilitation

Condition: The anterior cruciate ligament (ACL) is the part of the knee that connects the thigh bone (femur) to the larger bone in the lower leg (tibia).

Background: ACL injuries are common among athletes. There are about 100,000 ACL injuries each year. They occur when the athlete suddenly stops, turns or makes cutting moves, or jumps and lands awkwardly.

Risk Factors: ACL injuries are 3 to 7 times more common in women than men. Differences in anatomy, muscles, nerves, hormones, and the environment may affect the risk of injuring the ACL. Playing sports on artificial turf increases the risk of an ACL injury. Skiing also increases the risk of injuring the ACL.

History and Symptoms: Patients describe feeling a “pop” or that their knee is giving way. Swelling and pain usually follow. The athlete usually will not be able to continue with the activity. In people with repeated ACL injuries, there is often damage to other structures in the knee.

Physical Exam: With the patient on her back, the doctor will hold the thigh and try to move the lower leg forward. This is called the Lachman test. If the leg can be moved it means the ACL is damaged.

Diagnostic Process: X-rays, ultrasound, and MRI are used to see if the ACL has been injured, how badly, and if there is other damage in the knee.

Rehab Management: Rehab will focus on protecting the knee from more damage by limiting activity, using braces and crutches, and getting physical therapy to improve strength and stability. Surgery may be needed if the ACL needs to be rebuilt.

Other Resources for Patients and Families: Support from family and friends can help the athlete deal with depression and disappointment from not being able to compete.